I'm pretty sure the N51 has different injectors than the N52. I messed around in RealOEM one evening trying to figure out the differences between various N52s and also included the N51. I don't know if the injectors would affect power capability but they could.

Good point, it also could just be due to the lower compression. I'm still excited because this tune seems to need the 3 stage intake in order to get peak gains and the N51 should already have it. Regardless it would be a great bonus to those who have an N51 128i if we could spend $900 and gain 30 hp. If that's the case I will be forever grateful that I purchased mine while living in Rhode Island.

Evolve should send me a unit for research and development - I'll foot the bill for the dyno runs and send you guys charts and data. My N51 is still stock and only has 46,000 miles on it!!!